Kick it, Bunny!

This achievement is known to be buggy, and is flagged as such.

Here's what worked for me

Stand in one spot, smash over and over, and collect the random crap which shoots out from the ground (highlighted by a column of light).

I didn't move from the initial area, and unlocked all the achievements digging in that one spot. I dug for about 20 minutes, non stop, before the achievement popped. You have to pick up the items you dig up.

From the comments:

You can influence what you dig up by digging in the area of each kick it puzzle. For example, if you dig up in the Wolf gameplay area, you can get a wolf item.

This achievement will unlock in a few minutes.